This invention relates to agricultural baling machines and more especially to such machines known as round balers which produce cylindrical bales of crop material.
When round balers were first introduced, a completed bale was wrapped with twine in order to retain its shape during subsequent handling, just as the previous rectangular bales were tied with twine. However, in order to achieve satisfactory wrapping of a round bale, the twine has to be reciprocated back and forth along the length of the formed bale as the latter is rotated. This is relatively time consuming which is disadvantageous, bearing in mind that the formation of the next bale cannot be commenced until the formed bale has been wrapped and discharged from the machine.
With this problem in mind, it has been proposed to wrap a round bale with a sheet of synthetic plastics material. The wrapping of a round bale with a sheet material requires appreciably less time when compared with that taken to wrap a bale with twine or ribbon-like synthetic plastics material because only one and a half to two wraps are required. However, the use of such sheet material has generated a new problem, namely that of securing the wrapping, and numerous attempts have been made to solve this difficulty. To this end, it has been proposed to replace the solid sheet synthetic plastics by netting which self-adheres to a formed bale without the need to take any special steps in this respect. Such a disclosure is made in U.S. Pat. No. 4,569,439 and in U.S. Pat. No. 4,599,844 there is disclosed a specific arrangement for severing applied netting from a source roll thereof.
While the use of netting has been found satisfactory, there is one problem associated therewith which also tends to be present in the use of solid sheeting. The problem is that of the material reducing in width as it is pulled from the source roll and thus not being utilized to full advantage in wrapping a bale.